This sounds a lot like the way the M3's and M22's compare (Except for more difficult placement).

Owning both I find this :

The M3's are ever so slightly tipped up in bass and the M22's are just a bit more airy and open with some of the best midrange and treble this side of $2-3000 .

With a good sub .... the M22's are simply amazing .

The M3's are fantastic (and less needy of a sub)

The bottom line is they are all VERY good speakers indeed .